There may be instances in which data *gasp* resides outside of SharePoint, but still within the scope of the enterprise’s operations, and you will want to incorporate this data into the SharePoint platform. As an example, you may have a database of all your sales opportunities in Chicago, Milwaukee, and Madison but would like to have this data available on your “Sales Team Site” within SharePoint.

SharePoint Enterprise Content Management (ECM) is just that… the management of the Enterprise’s content. The question then becomes how to interact with information in databases outside of SharePoint, but manage the content within SharePoint. The solution is through the use of External Content Types and External Lists.